pretend we are still 2.13.9

include/ExtensionClass/ExtensionClass.h

@@ -208,8 +208,10 @@ static PyExtensionClass NAME ## Type = { PyObject_HEAD_INIT(NULL) 0, # NAME, \
   PyExtensionClassCAPI->PyECMethod_New_((CALLABLE),(INST))
 
 /* Return the instance that is bound by an extension class method. */
+// Pyston change: cannot access the member of PyMethodObject in Pyston directly.
 #define PyECMethod_Self(M) \
-(PyMethod_Check((M)) ? ((PyMethodObject*)(M))->im_self : NULL)
+(PyMethod_Check((M)) ? PyMethod_GET_SELF(M) : NULL)
+// (PyMethod_Check((M)) ? ((PyMethodObject*)(M))->im_self : NULL)
 
 /* Check whether an object has an __of__ method for returning itself
    in the context of it's container. */

setup.py

@@ -25,11 +25,16 @@ with open('CHANGES.rst') as f:
     CHANGES = f.read()
 
 # PyPy won't build the extension.
+# Pyston change: if there has Python implementation
+# I think it is better use it, because Pyston JIT can track objects
+# which created by pure Python, and apply some JIT optimization.
+# But cannot apply optimization on C extension for now.
 py_impl = getattr(platform, 'python_implementation', lambda: None)
 is_pypy = py_impl() == 'PyPy'
+is_pyston = py_impl() == 'Pyston'
 is_pure = 'PURE_PYTHON' in os.environ
 py3k = sys.version_info >= (3, )
-if is_pypy or is_pure or py3k:
+if is_pypy or is_pyston or is_pure or py3k:
     ext_modules = []
 else:
     ext_modules=[Extension("Acquisition._Acquisition",
@@ -41,7 +46,7 @@ else:
 
 setup(
     name='Acquisition',
-    version='4.2.2',
+    version='2.13.9',
     url='https://github.com/zopefoundation/Acquisition',
     license='ZPL 2.1',
     description="Acquisition is a mechanism that allows objects to obtain "
@@ -69,8 +74,10 @@ setup(
         "Programming Language :: Python :: Implementation :: PyPy",
     ],
     ext_modules=ext_modules,
+    # Pyston change: due to we switched to pure Python implementation.
+    # The version of ExtensionClass is not important any more.
     install_requires=[
-        'ExtensionClass >= 4.1.1',
+        'ExtensionClass<4.0.dev',
         'zope.interface',
     ],
     include_package_data=True,